The Ruger 10/22 is the most popular .22 caliber rifle in the US. The AR-15 is the most popular center fire rifle in the US. Both weapon systems are also among the most commonly modified firearms, with a wide variety of aftermarket products available for both systems.
One of the most common modifications to the 10/22 is the attachment of an accessory rail (e.g. picatinny rail) to the top of the receiver using the four factory-installed screw holes. The rail is oftentimes used to mount a scope.
The most common embodiment of the AR-15 is known as the A4 or Flat Top Profile (AR-15 and A4 are sometimes described generically herein as “AR”). This design has a picatinny rail on the top of the AR-15 upper receiver in place of the carry handle that was present on the original design. This facilitates the mounting of optics on the rifle which was difficult with the original carry handle configuration of the upper receiver.
One of the more common modifications of the AR-15 is the replacement of the handguard. Handguards for the AR-15 are available for a wide variety of specialized applications and the designs often include attachment points for additional accessories such as sighting systems, sling mounts, flashlights, sighting lasers, and bipods. Handguards for the AR-15 are attached by two methods. In the original design, the handguard is captive between brackets attached to the barrel nut and the front sight. The second design is attached using only the barrel nut (generally a specially designed one for the particular handguard, sometimes including a barrel sleeve). These second-type designs are generally considered superior to the original in both simplicity and because the barrel is not contacted by the handguard (i.e. the barrel is “free-floated”), which improves accuracy. The replacement handguards often have a picatinny rail on the top surface that fits flush to and aligns with the picatinny rail on the A4 type AR-15 upper receiver.
Therefore, a system that attaches to the 10/22 like the factory rail/scope mount but that additionally incorporates the barrel nut threads of the AR4 upper receiver allows the wide range of handguards and accompanying accessories available for the AR-15 to be utilized on the 10/22. If the chassis system also incorporated attachment points for AR-15 buffer tubes/stocks and grips, it would allow the similarly wide variety of AR-15 stocks and grips that are available to be utilized on the 10/22 platform.
Other objects and advantages of the subject technology, in addition to such other objects and advantages that may be apparent to those of skill in the art after studying the subject technology, include:
The upper chassis of the subject technology has the same geometry and dimensions as the top and front portion of the AR upper receiver (including the distance from the top of the picatinny rail to the center of the bore, so all free float handguards with upper picatinny rails designed for the AR will align flush and level with the picatinny rail on the upper chassis, and optics and sights designed for the AR will attach and function properly. In one known system (manufactured by Nordic), the upper chassis rail is higher than the handguard rails and there is a horizontal gap between the two.
Removal of the lower chassis of the subject technology for purposes of cleaning or servicing the weapon only requires removal of the single factory takedown screw. Removal of the lower chassis does not require loosening or removal of the top portion of the chassis, so the “zero” of sighting systems is not affected. The other known design requires the picatinny rail to be removed prior to removal of the lower chassis.
The upper chassis of the subject technology has wings that fit onto the barrel block to provide lateral and rotational strength.
The lower chassis has wings that fit over the wings of the upper chassis, providing improved lateral and rotational strength.
Tactile surfaces (aka side cuts) on the lower chassis reduce weight and also provide reference points (tactile feedback) for the trigger, safety, and the bolt release.
The upper chassis of the subject technology can be used without the lower chassis of the subject technology. This aspect allows an AR scope/handguard mount to be used with factory Ruger stocks and aftermarket stocks with only minor modification in that the front portion of the Ruger stocks and aftermarket stocks must be truncated.
In one aspect, the subject technology has only two main parts (upper and lower chassis) as opposed to three (i.e. the upper chassis has an integrated picatinny rail). Conventional systems require removal of the picatinny rail before the lower chassis can be removed.
In one aspect, the subject technology has a retention washer on the takedown screw. A nylon washer fits within a counter bore (aka recess) on the upper surface of a protrusion of the lower chassis (so as to be disposed between the lower chassis and the receiver). A compression washer (aka lock washer) is used on the bottom surface of the lower chassis.
In one aspect, the subject technology incorporates AR-style barrel nut threads that allow attachment of AR-15 free-float handguards, with an additional barrel spacer configured to cause the picatinny rail of an AR4 style handguard to fit properly against the picatinny rail of the subject technology. In other aspects, the barrel spacer ring can be resized (e.g. grinded) to provide a better fit with some handguards without altering the original mount. Thus, replacing the barrel spacer allows use with different handguards.
In one aspect, the upper chassis of the subject technology incorporates the geometry of the top and front portions of an A4 AR-15 upper receiver into a mount with an internal geometry that matches the top and front portions of the Ruger 10/22 receiver. The mount attaches to the 10/22 receiver by utilizing the four factory-installed scope mount holes that are located on the top surface of the 10/22 receiver. The mount closely conforms to the upper surface of the 10/22 receiver and has wings that engage the barrel block. These features provide additional lateral and rotation stability to the chassis/receiver system. Since the exterior dimensions and geometry of the upper chassis match the exterior dimensions and geometry of the AR-15, all free float style handguards designed to attached to the AR-15 utilizing the barrel nut are compatible.
In one aspect, the lower chassis attaches with a single takedown screw located just forward of the magazine well. The lower chassis has AR-style attachment points for the buffer tube/stock and grip, allowing standard AR parts to be utilized (some aftermarket grips may need to be trimmed if dimension differ significantly from the standard AR grip). Lower wings in a front portion of the lower chassis engage wings on the upper chassis to provide additional stability.
In one aspect, the barrel spacer (aka barrel washer) is machined from 6061 aluminum and replaces the collar on the AR barrel allowing for proper fit of free-float handguards. A buffer tube ring maintains proper alignment of the buffer tube/stock during assembly. This is laser cut from steel and pressed into shape. A plastic grip spacer provides a smooth transition between the AR style grips and the 10/22 trigger guard.